Conventionally, forces in micro and nano ranges have been measured using MEMS (Micro Electro Mechanical Systems) transducers (converters) such as piezo elements, strain gauges, piezo resistors, capacitive and optical force sensors. Piezo element sensors are suitable for detecting dynamic forces, but not suitable for detecting static forces because of their structures. On the contrary, capacitive sensors are excellent in sensitivity and stability as compared with piezo element sensors (see, for example, patent literature 1). Further, optical force sensors are big in construction and expensive, but can realize a most sensitive force measurement in the present circumstances.
Some of conventional MEMS transducers include a cantilever and a laser displacement meter (see, for example, patent literature 2). This MEMS transducer is utilized in atomic force microscopes (AFMs) and the like and constructed such that, when a tip fixed to the leading end of the cantilever comes into contact with a measurement object, the cantilever is deflected, this deflection is detected by the laser displacement meter and a micro force is calculated based on the detected displacement amount.